/Engine/Source/Runtime/Core/Public/Misc/DataDrivenPlatformInfoRegistry.h
Gets a list of all known confidential platforms (note these are just the platforms you have access to, so, for example PS4 won't be returned if you are not a PS4 licensee)
static const [TArray](API\Runtime\Core\Containers\TArray)< [FName](API\Runtime\Core\UObject\FName) > & GetConfidentialPlatforms()